Device for resuming weaving on a wave weaving loom



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United States Patent 3,498,336 DEVICE FOR RESUMING WEAVING ON A WAVE WEAVING LOOM Heinrich Fend, Zurich, Switzerland, assignor to Werkzeugmaschinenfabrik Oerlikon Buhrle & C0., Zurich, Switzerland Filed June 26, 1968, Ser. No. 740,293 Claims priority, application Switzerland, June 27, 1967, 9,101/ 67 Int. Cl. D03d 41/00, 49/60 US. Cl. 139-12 Claims ABSTRACT OF THE DISCLOSURE A wave weaving loom having a cloth feed roll and beating-up members forming a beating front serving for the beating up of weft threads against a beat-up line of the cloth. A drive member varies the direction of The invention relates to a device on a wave weaving loom having a cloth feed roll, having beating-up members which form a beating front, which front serves to beat up weft threads at the beat-up line of the cloth, having a drive member to vary the direction of the picked weft threads and the direction of the beating front relative to one another.

A mechanism of this kind is known having setting members to set the speed of the drive member in order to be able to adapt it to the speed of rotation of the cloth feed roll. In this known mechanism, a two-armed lever for example is provided wherein the ratio of the length of the two arms is infinitely variable in order that the speed of the drive member from a constant-speed drive may be adapted to the speed of the cloth feed roll. These setting members are relatively complicated and diflicult to operate. It is the object of the invention to avoid these setting members and it is characterised by members which are connected on the one hand to the feed roll and on the other hand to the drive member in order to regulate the speed of the drive member depending on the speed of rotation of the feed roll.

The mechanism according to the invention can be used for resuming weaving on a wave weaving loom after work has been interrupted, for example because of a breakage in a weft thread when weft threads already picked have been removed from the cloth.

When the weaving is resumed, beating front and beatup line can be brought into their initial relative position again while the next weft thread is being picked.

Two examples of embodiments of the invention are described in detail below with reference to the accompanying drawing in which:

FIGURE 1 shows a part of a loom with rocking shafts equipped with a first embodiment of said mechanism, illustrated in perspective from the right-hand side;

FIGURE, 2 shows a part of a loom with rocking shafts equipped with the second embodiment of said mechanism, illustrated in perspective from the left-hand side;

FIGURE 3 is a diagrammatic plan view showing the state of the warp and of the cloth on a loom with rockice ing shafts, as shown in FIGURE 2, after a weft thread has broken and the machine has been stopped;

FIGURE 4, in a similar view to FIGURE 3, shows the state of the warp and of the cloth after their adjustment immediately before weaving is resumed;

FIGURE 5 shows the same elements in a similar illustration, at another stage after weaving has been resumed;

FIGURE 6 shows part of the loom illustrated in FIG- URE 1 in a view on the line VIVT in FIGURE 1;

FIGURE 7 shows a section on the line VIIVII from FIGURE 6;

FIGURE 8 shows a diagram of the mode of operation of the loom with rocking shafts as shown in FIGURES l, 6 and 7;

FIGURE 9 shows a section through a shuttle driver in accordance with the first example;

FIGURE 10 shows a section through a shuttle driver and a beater in accordance with the second example of an embodiment;

The warp 10 forms a number of sheds 11 of which only the shed 11 is illustrated in FIGURE 1. This warp 10 runs off the Warp beam, not illustrated, of a wave weaving loom.

The material produced on this wave weaving loom is wound on a cloth beam likewise not illustrated in FIGURE 1. A feed roll 13, which is driven by a stepping mechanism not illustrated, serves to advance the cloth 12. The warp 10 runs from the warp beam over a tension beam not illustrated to a group of shafts of which only two shafts 14 and 15 are illustrated for the sake of clarity, and from there to the beat-up line 16 of the cloth.

The two shafts 14 and 15 together with the other shafts not illustrated produce said sheds which travel in waves following one another across the width of the cloth. These sheds are formed by the upwardly deflected warp threads 17 and the downwardly deflected warp threads 18. A lower group of warp threads 18 is held by the shaft 14 and an upper group of warp threads 17 is held by the shaft 15. A shuttle 19 runs in each such travelling shed.

Each shuttle 19 is guided in a row of so-called shuttle drivers 20. The drive of this row of shuttle drivers 20, only one of which is illustrated in FIGURE 1, is effected from a row of cams not illustrated. This row of cams is mounted on a camshaft not illustrated which rotates continuously when the loom is in operation. A rod 21 for each shuttle driver 20 is reciprocated by these cams along a plane parallel to the warp threads 10, between an invariable front end position 21a and an invariable rear end position 21b, in a guide 22 provided in the machine frame. In FIGURE 1, the front end position 21a is only indicated in broken lines while the rear end position 21b is illustrated in full lines. In the rear end position 21b, the shuttle driver 20 secured to each rod 21 projects, into the shed 11 traveling past and penetrates through the group of lower warp threads 18.

When the rod 21 is in the front end position 21a, the shuttle driver 20 is entirely outside the shed 11 as indicated by the driver 20a illustrated in broken lines.

A dovetailed recess 23 (FIGURE 9) and a seating 24 parallel to the direction of the displacement of the shuttle driver are formed in the upper portion of each shuttle driver 20a for each of the shuttles travelling past. Each shuttle 19 has, at its underside, a rib 26 (see FIGURE 9) which fits into the recesses 23 in the shuttle drivers 20. (The shuttle 19 rests with a plane surface 28 situated in front of said rib 26 (FIGURE 9) on the seating 24 on the shuttle driver 20 in question). The cycles of reciprocation of the individual rods 21 and of the shuttle drivers 20 mounted thereon are staggered in time in such a manner that the substantially vertical rear boundaries of the recesses 23 form a sinuous line which is displaced continuously from left to right at right angles to the direction of movement of the rods 21. In FIGURE 8, the shuttle drivers and beaters 30, described below, are illustrated in section 30a in FIGURE 8 represents the line in which the leading edge of each beater 30 comes to lie in its front end position designated in the same manner as in FIGURE 1. The corresponding line for the rear end position of the beaters 30 is designated at 30b. b indicates the distance through which the leading edges of the beaters travel between two end positions. The sinuous line comprises front peak points which are joined together by a line 25b in FIGURE 8 and rear peak points which are joined together by a line 25a. Said vertical rear boundaries of the recesses 23 reach their front and rear end positions respectively at these peak points 25b and 25a. The total travel is designated by a in FIGURES 1 and 8. The backwardly directed loops of this sinuous line lie inside the travelling sheds 11.

The shuttle 19 is thus compelled, as a result of the reciprocating motion of the shuttle driver, to travel across the width of the cloth with this loop of the sinuous line in the corresponding shed 11 at right angles to the direction of displacement of the rods 21, the weft thread 27, out to length and present in the shuttle, (FIGURE 8) being introduced between the warp threads 17 and 18,

Behind the shuttle driver 20, each rod 21 carries a pin 29 on which there is pivotally mounted a beater 30 constructed in the form of a lever, Each beater 30 extends upwards above this pin 29 in the same plane as the associated shuttle driver 20 between adjacent warp threads 17 and 1-8 that it projects above the upper warp thread 17 even when the shed is fully open. Adjacent beaters 30 support each other mutually in the lateral direction by means of supporting shoes 31 secured to their upper ends. These supporting shoes 31 comprise parallel lateral sliding surfaces and are sufiiciently long to touch one another even when adjacent beaters 30 provided therewith form the maximum angle with one another occurring in operation.

Each beater 30 is pivotally mounted by its forked end 32 on a pin 33. This pin 33 is secured to a slide 34. Of these slides 34, the first, fourth, seventh etc., that is to say every third one (FIGURE 6), engages with two pins 35 and 36 in a groove 37 (FIGURE 6) parallel to thedirection of movement of the drive rods 21, in a stationary cross bar 38 of the machine frame. Since the slides 34 are in lateral contact with one another they are all guided parallel to said direction of movement in this manner. Their undersides rest on an adjusting lever 39 which is pivotally mounted on the cross bar 38 on a vertical pin 40 at the rear of the machine in FIGURE 1 and which comprises a longitudinal groove 41 in its upper side. Each slide 34 carries a pin which engages in this longitudinal groove 41 and which, in every third slide is formed by the lower portion of said pin 35 and in the other slides is a separate pin 42.

In order to make the drawing clear, considerably fewer slides 34 are shown in FIGURES 6 and 7 than the machine does in fact comprise and than there are beaters 30 indicated in FIGURE 8, each of which require such a slide.

While the rods 21 are reciprocating between the invariable end positions 21a and 21b (FIGURE 1), they cause each beater 30 to swing backwards and forwards between a front end position 30a (FIGURE 8) and a rear end position 30b (FIGURE 8), through a substantially constant angle, with the associated pin 33 as a pivot pin 33 as a pivot point. These end positions 30a and 3012 are not invariable, however, because the slides 34 which carry the individual pins 33 can be displaced differently by pivoting the lever 39 about the pin 40'. In the course of this, the individual slides 34 are displaced parallel to one another, through distances which are proportional to the spacing of the axis of their guide grooves 37 from the axis of the pin 40 and hence increase linearly from the left-hand side of the machine in FIGURE 7 to the right-hand side. For example, if the lever 39 is pivoted out of a position in which its longitudinal groove 41 extends at right angles to the guide grooves 37, backwards into the position shown in FIGURE 7, then each slide 34 comes to lie somewhat further towards the rear than the adjacent pin towards the pin 40, that is to say towards the left-hand side of the machine. Accordingly, the fields of traverse 30a and 30b (FIGURE 8) of the individual beaters 30 are shifted forwards to an extent increasing from the left-hand side of the machine to the right.

The pivoting of the adjusting lever 39 is effected by a working cylinder 43 in which there is mounted a double acting piston 44. This piston 44 is articulately connected through a piston rod 45 to an extension 46 on the adjustinglever 39. The working cylinder 43 is secured to the machine frame and comprises two pipelines 47 and 48 which are connected to a source of compressed air, not illustrated, through a three-way cook 55. Depending on the position of the three-way cock 55, compressed air can act on the piston 44 from the front through the pipeline 47 or from the rear through the pipeline 48, as a result of which the adjusting lever 39 can be displaced either forwards against a fixed stop 49 or towards the rear against an adjustable stop 54 which is described below.

The pivoting of the adjusting lever 39 is controlled through a rod 50 which is displaceable along a plane parallel to the warp threads, in a guide, not illustrated, in the machine frame. In its central portion, this rod 50 comprises teeth 51 which are in mesh with a toothed segment 52. This rod 50 is articulated by one end to the adjusting lever 39 and comprises a stop 53 at its other end. This stop 53 cooperates with an eccentric disc 54 adjustable by hand.

The eccentric 54 enables the inclined position of the adjusting lever 39 to be adapted to the particular density of the weft threads and the spacing between the successive shuttles. Since this spacing is generally a given quantity on a specific loom, it is sufiicient to provide the eccentric 54 with a scale on which the various densities of weft thread are entered.

If the line 48 is connected to the source of compressed air through the three-way cock 55 which the line 47 is vented, the adjusting lever 39 is urged towards the stop 49 by the piston 44 with the extension 46 and the adjusting lever 39 is then perpendicular to the grooves 37 in the cross bar 38. In this case, the beating front formed by all the beating-up members 30 is at right angles to the direction of the warp threads. On the other hand, if the line 47 is connected to the source of compressed air through the three-way cook 55 while the line 48 is vented, the adjusting lever 39 can be pivoted towards the rear to such an extent that the stop 53 on the rod 50, articulated to the adjusting lever 39, strikes against the eccentric disc 54. The adjusting lever 39 is then in the position illustrated in FIGURE 6. In this case, the beating front of the beaters 30 is no longer at right angles to the direction of the warp threads.

The toothed segment 52, which is in mesh with the teeth 51 on the rod 50, is secured to an arm of a bellcrank lever 56 which is mounted on a pin 57 secured to the machine frame. Articulated to the other arm of the bell-crank lever 56 is a pawl 58 which is urged against a ratchet wheel 59 under the action of a spring. This ratchet wheel 59 is likewise mounted on the pin 57 and rigidly connected to a gearwheel 60. Pawl 58 and ratchet wheel 59 thus form a coupling effective in one direction of rotation. The gearwheel 60 is in mesh, through a further gearwheel 61, with a third gearwheel 62 secured to the feed roll 13.

When the m is in operation, the gearwheel 62, to-

gether with the stepping roll, turns in the direction of rotation indicated by an arrow (FIGURE 1). Thus the gearwheels 61, 60 and the ratchet wheel 59 also rotate in the direction of rotation indicated by arrows. The bellcrank lever 56 can turn in the direction of the arrow about the pin 56 until the rod 50 in mesh with the toothed segment 52 of the bell-crank lever 56 strikes with its stop '53 against the eccentric disc 54. On further rotation of the ratchet wheel, the pawl 58 jumps over the teeth of the ratchet wheel 59.

When the rod 50 is driven fully forward by the piston 44, then the bell-crank lever 56 turns in clockwise direction (FIGURE 1) until the pawl 58 strikes against a stop 75 as a result of which it comes out of engagement with the ratchet wheel 59. In this position, the ratchet wheel 59 and hence also the stepping roll is freely rotatable Without any pivoting of the beaters 30 being effected.

The mode of operation of a wave weaving loom, which is equipped with the mechanism described, is explained below with reference to FIGURE 8.

During normal operation of the loom, the three-way cock 55 is set in such a manner that the compressed air acts on the piston 44 through line 47 and the adjusting lever 39 is in the position shown in FIGURE 6, that is to say the stop 53 on the rod 50 articulated to the adjusting lever 39 bears against the eccentric disc 54.

As can be seen from FIGURE 8, the beaters 30 are displaced in accordance with a travelling sinuous line in the same manner as the shuttle drivers 20. As a result of the inclined position of the lever 39, the heaters 30 are offset in relation to the shuttle drivers 20 to a decreasing extent from left to right. The line 30a is identical with the beat-up line 16. It forms a small angle a with the direction perpendicular to the warp thread planes, that is to say with the direction of the weft threads 27 already picked and beaten up in the cloth 12.

The inclined position of the beating front 16 in relation to the direction of the picked weft threads is necessary in every wave weaving loom as explained in British Patent No. 1,108,735 corresponding to U.S. Patent No. 3,346,017 granted Oct. 10, 1967.

If a thread breakage occurs in the weft, the machine is stopped and the adjusting lever 39 is pulled forwards at the right-hand side of the machine, by actuating the three-way cock 55 in such a manner that the compressed air acts on the piston 44 through the line 48 and the line 47 is vented. The piston 44 then pulls the adjusting lever 39 forwards until the extension 46 strikes against the stop 49. As a result, the lines 30a (beating front) and 30b which define the end position of the beaters 30 are turned in counterclockwise direction seen from above (FIGURE 8) and come to stand at right angles to the warp threads 10 and parallel to the weft threads 27 of the cloth 12, as indicated by the lines 30a and 30b.

The shuttles present in the region of the web of fabric are then removed as well as the torn weft threads 27a and all the weft threads 27i, 27h, 27d, 27c which have merely been partially picked into the cloth after it, and the lowest weft thrad 27b picked completely into the cloth is brought back to the beating front 30a by withdrawing the warp. The machine can then be set in operation again, that is to say both the shuttle drive as well as the warp delivery and cloth feed are switched on again. In the course of this, care must be taken to ensure that during the time which the first shuttle 19 needs to travel through the full width of the cloth, the adjusting lever 39 gradually resumes its initial position, that is to say is restored to its normal operating position. For this purpose, when the loom is started up, the three-Way cock is turned in such a manner that compressed air is admitted to the piston 44 from the front through the line 47. A displacement of the adjusting lever '39 now takes place as follows. The pawl 58 is lifted from the stop 75 and engages in a gap between the teeth in the ratchet wheel 59 is turned step-by-step by the feed roll 13 through 6 the gearwheels 62, 61 and 60. The feed roll 13 moves the cloth 12 on by one pitch of the weft threads after each beating up of the cloth, that is to say every time a new shuttle 19 enters. Thus the distance which the ratchet whel covers during each escapement step of the roll 13 depends on the pitch of the weft threads. Since the adjusting lever 39 also has to be pivoted through the angle depending on the density of the weft threads, it always reaches its initial position after a specific number of escapement steps which depends on the number of shuttles present simultaneously over the whole width of the cloth. As a result it is possible to obtain a suitable transmission ratio for the gearwheels 62, 61 and so that the adjusting lever 39 returns to its initial position during the time which one shuttle 19 takes to travel through the full width of the cloth.

The right-hand end of the beating front now turning back from the line 30a to the line 30a follows the feed of the cloth 12 depending on the speed of rotation of the feed roll 13 because the members 56 to 62 are connected on the one hand to the feed roll 13 and on the other hand to the drive member 50, while the left-hand end of the beating front remains stationary so that space for the further weft threads to be beaten up is afforded by the advance of the warp threadsin front of the beating front.

In FIGURE 2, a second example of an embodiment is illustrated which differs from the example described essentially in that it is not the beating front of the beaters but the beat-up line of the fabric which is pivoted.

According to FIGURE 2, the warp 10 runs off a warp beam 63 over a tension beam 64, a first deflection roll 65 and a guide roll 66 to a group of shafts 67 and from there to the beating front 16. The shafts in the group of shafts 67 are not illustrated in the drawing. By deflecting its threads alternately upwards and downwards they form from the warp 10, sheds 11 which travel successively in waves over the width of the cloth between the upwardly deflected warp threads 17 and the downwardly directed warp threads 18. A shuttle 19' also travels in each such travelling shed, the first of which is shown diagrammatically in longitudinal section at the front edge of the warp in the drawing.

The shuttles 19 are driven by members 68 which are reciprocated individually in equal cycles in the longitudinal direction of the machine, that is to say each along a plane extending perpendicular to the axes of the warp beam 63 and the cloth beam, with such a mutual phase displacement that they form wavy loops of the same shape adapted to the shape of the shuttle 19, travelling across the width of the cloth across the warp threads 10 in the direction of the arrow 69 (FIGURE 2). Such a member 68 is secured to a rod 21 as shown in FIGURE 10. This rod is driven by a series of cams not illustrated. This series of cams is mounted on a camshaft not illustrated which rotates continuously when the loom is in operation. Each member 68 is driven by these cams through the associated rod 21. Each member 68 consists of a portion 68a which comprises a dovetailed recess 23 and a seating 24 parallel to the direction of dis placement of the member 68 for the particular shuttle 19 travelling past, and of a second portion 68b which is adapted to beat up the weft thread.

The shuttles 19 are held and entrained by the members 68. Thus a portion of each member 68 acts as a shuttle driver 68a in the region of each passing shuttle 19. (FIG- URE 10). Between these regions, another portion of each member 68 acts as a beater 68b in that it beats out a weft thread 27 (FIGURE 3) which the last shuttle 19 travelling past the member 68 in question has picked in the shed 11, against the cloth 12 already produced, as far as the straight line 16 extending parallel to the axes of the warp beam 63 and the cloth beam and termed beating front.

Finally, each weft thread is tied into the cloth being formed by crossing the warp threads 10 at the point in questiondepending on the weaving pattern--by means of the corresponding shafts of the group of shafts 67.

From the beating front 16, the cloth 12 runs over a second guide roll 70, a second deflection roll 71 and betwen a control and breast beam 72 which is driven stepby-step at an adjustable angle of speed by a drive not illustrated, through gearwheel '61 and gearwheel 62 and which causes the uniform advance of the cloth over its whole width, and through a pressure roll 73, illustrated in broken lines in FIGURE 2, on to the cloth beam, not illustrated, on which the cloth is wound. When the machine is in operation, the warp threads are displaced continuously from the warp beam 63 towards the beating front 16 and from there, as components of the cloth 12, on to the cloth beam. The tension beam 64, the two guide rolls 66 and 70 and the breast beam 72 are mounted in the two side walls of the loom frame with immovable axes parallel to one another and to the axes of the warp beam 63 and the cloth beam. Only the left-hand side wall 74 is indicated in FIGURE 2, large parts being broken away in order to show elements behind these parts.

The two deflection rolls 65 and 71 are pivotally mounted in a manner not illustrated in the right-hand side wall while their left-hand ends are held for displacement in arcuate slots 77 and 78. The longitudinal profile of the slots 77 and 78 is selected in such a manner that the lefthand ends of the deflection rolls 65 and 71 are adjusted not only'upwards and downwards but also towards the front and rear in such a manner that the forces caused at these rolls by the tension of the warp threads 10 or the cloth 12 have minimum components parallel to the axis of the roll in question; thus a lateral drift of the warp threads or of the fabric is counteracted while the machine is in operation.

The deflection roll 71 is mounted in the right-hand side wall at such a height that, when its axis lies parallel to that of the guide roll 70 and of the breast beam 72, it just touches the cloth 12 running from this guide 70 towards the breast beam 72. This is the case when the deflection roll 71 is at the upper end of the slot 78. When the left-hand end of the deflection roll 71 is displaced downwards, the left-hand end of the roll 65 is displaced upwards, as described below, and in the course of this the path of the wrap threads 10 from the beating front 16 to the breast beam 72 is lengthened, that is to say the individual warp threads 10 are displaced forwards by diiferent amounts increasing from right to left during the downward pivoting of the deflection roll 71 in the region of the beating front 16. The consequence of this is that, in the region of the beating front 16, the weft threads 27 originally directly parallel to the beating front 16 form a small angle with the beating front 16 and this angle is the greater the lower down in the slot 78 is the left-hand end of the deflection roll 71.

In order to compensate for this different displacement ofthe warp threads 10 in the region of the beating front 16 without varying the mutual position of warp beam 63 and cloth beam, without varying the length of wrap thread between the two and without varying the warp-tread tension, the deflection roll 65 is pivoted upwards about its bearing position in the right-hand side wall during the downward swinging of the deflection roll 71 in such a manner that the path of each warp thread 10 from the tension beam 64 to the guide roll 66 is shortened precisely by the same amount as the path of the same warp thread 10 is lengthened from the guide roll 70 to the breast beam 72. For this purpose, the left-hand end of the rear deflection roll 65 is displaced in the slot 77 and the left-hand end of the front deflection roll 71 is displaced in the opposite direction in the slot 78 by means of a common lever 78a, each through a link 79 or 80, each of which is articulated to this lever 78a 'by means of a pin 81 or 82 respectively.

As in the first example, the pivoting of the lever 78a is caused by the working cylinder 43 in which there is mounted the double-acting piston 44. This piston 44 is articulately connected, through the piston rod 45, to the extension 46 on the rod 50. The working cylinder 43 is secured to the machine frame and comprises the two pipelines 47 and 48 which are connected to a source of compressed air, not illustrated, through the three-way cock 55. Depending on the position of the three-way cock 55, compressed air can act on the piston 44 from the front through the line 47 or from the back through the line 48, as a result of which the rod 50 can be displaced either forwards against the fixed stop 49 or backwards against the adjustable stop 54.

The rod 50 which is displaceable along a plane parallel to the warp threads in a guide, not illustrated, in the machine frame, is articulated, as its rear end, to one arm of a bell-crank lever 83. This bell-crank lever 83 is pivotable about a pin 84 secured in the side wall 74. The other arm of the bell-crank lever 83 is articulated to the lever 78a through a link 85. In its central portion, the rod 50 comprises the teeth 51 which are in mesh with the toothed segment 52. The rod 50 comprises, at its front end, the stop 53 which co-operates with the eccentric disc 54 adjustable by hand.

If the line 48 is connected to the source of compressed air through the three-way cock 55, while the line 45 is vented, then the rod 50 is displaced forwards, the bellcrank lever 83 is pivoted in counterclockwise direction and pivots the lever 78a likewise in counterclockwise direction through the link 85. As a result of this movement of the lever 78, the front deflection roll 71 comes with its lefthand end into the uppermost position and the axis of the deflection roll 71 is then parallel to the axis of the breast beam 72 and the cloth beam. At the same time, the rear deflection roll 65 is pivoted with its left-hand end into its lowest position. In this position of the two deflection rolls 71 and 65, all the weft threads 27 in the region of the beating front are parallel thereto.

On the other hand, if the line 47 is connected to the source of compressed air through the three-way cock 55 while the line 48 is vented, the rod 50' can be displaced towards the rear until the stop 53 on the rod 50 strikes against the eccentric disc 54. The deflection rolls are then in the position shown in FIGURE 2. In the region of the beating front, the weft threads are inclined in relation to the beating front by the angle defined above.

The toothed segment 52 which is in mesh with the teeth 51 on the rod 50 is secured to an arm of the bellcrank level 56 which is mounted on the pin 57 secured to the machine frame. Articulated to the other arm of the bell-crank lever 56 is the pawl 58 which co-operates with the ratchet wheel 59. The ratchet wheel is likewise mounted on the pin 57 and rigidly connected to the gearwheel 60. The gearwheel 60 is in mesh, through the gearwheel 61, with the third gearwheel 62 which is secured to the breast beam 72. When the loom is in operation, the breast beam 72 and hence the gearwheel 62 rotate in the direction indicated by an arrow (FIGURE 2). Thus the gearwheels 61 and 62 and the ratchet wheel 59 also rotate in the direction indicated by arrows.

The speed of the step-by-step rotation of the breast beam 72 depends on the number of weft threads picked per unit of time and hence on the shuttle speed and the number of shuttles working simultaneously. The transmission ratio of the gearwheels 60-62 is selected in such a manner that during the complete picking of one weft thread, that is to say when one shuttle has travelled the whole distance through the cloth, the deflection roll 71 has likewise executed its complete stroke.

The bell-crank lever 56 on which the pawl 58 is articulated and engages in a gap in the teeth in the ratchet wheel 59 under the action of a spring not illustrated, can rotate about the pin 57 in the direction of the arrow until the rod 50 in mesh with the toothed segment 52 of 9 .4 the bell-crank lever 56 strikes with its stop 53 against the eccentric disc 54. During the further rotation of the ratchet wheel 59, the pawl 58 jumps over the teeth of the ratchet wheel 59.

When the rod 50 is driven fully forwards by the piston 44, then the bell-crank lever 56 rotates in counterclockwise direction (FIGURE 2) until the pawl 58 strikes against the stop 75 as a result of which it comes out of engagement with the ratchet wheel 59. In this position, the ratchet wheel 59, and hence also the breast beam 72, is freely rotatable without the deflection rolls 65 and 71 being pivoted.

The mode of operation of the second embodiment described of the mechanism on a wave weaving loom is described below with reference to FIGURES 3 to 5.

In these figures, the warp threads are drawn vertical and the weft threads 27 transversely thereto. The shafts 67 serving to form the sheds are indicated as horizontal strokes. Here, the members 68 serve both as heaters 68b for beating up the weft threads 27 against the beat-up line 16 and also as shuttle drivers 68a for the displacement of the shuttles 19 as explained above. During undisturbed weaving, each weft thread 27a to 27h emerging from a shuttle 19 is beaten up against the beatup line by the beater 68b before the passage of the next shuttle. During their forward movement, the heaters reach the beating front 16.

If the front deflection roll 71 were in its uppermost pivoted position in which it still just touches the cloth 12 and its axis is parallel to that of the breast beam 72 and parallel to the beating front 16, then if the cloth 12 were not distorted the weft threads 27 would not be at right angles to the warp threads because the weft threads are inclined at an angle in relation to the beating front 16 in the region of the beating front 16. For a useful cloth, however it is necessary for the weft threads to be at right angles to the warp threads.

During undisturbed weaving, therefore, the left-hand end of the deflected roll 71 is in the low position in the slot 78 shown in FIGURE 2.

If, as already explained with reference to the first example, the weft thread 27a is torn at A as shown in FIG- URE 3 and if this weft thread 27a as well as all the weft threads 27b to 27h picked after it are removed from the cloth by hand and the shuttles 19 present within the width of the cloth are also emptied, then the three-way cock 55 is actuated by hand in such a manner that the compressed air acts on the piston 44 from the rear through line 48 while the line 47 is vented. Then the piston 44 displaces the rod 50 toward the right until the extension 46 on the rod 50 strikes against the stationary stop 49. The lever 78a is pivoted in counterclockwise direction through the bell-crank lever 83 and the link '85 and the left-hand end of the deflection roll 71 is displaced in the slot 78 as far as the upper end thereof through the links '80 and 79 so that the axis of this deflection roll 71 comes to lie parallel to the breast beam 72. The left-hand end of the rear deflection roll 64 on the other hand moves downwards in the slot 77.

The path of each warp thread 10 between the warp beam 63 and guide roll 65 is lengthened as a result while the path between the guide roll 70 and the breast beam 72 is shortened by the same amount. This amount increases from right to left over the width of the cloth. The portion of each warp thread which is between the guide rolls 66 and 70 and in the region of which there lies the beating front 16 is thus displaced towards the rear by a distance which increases from right to left. Although the increase in this displacement from the righthand edge to the left-hand edge of the cloth is not strictly linear so that each weft thread follows a gentle arc, nevertheless its deviation from a straight line is insignificant. The displacement is selected in such a manner that, through it, the original inclined position of the weft threads 27 is substantially cancelled out in the region of the beating front 16 and the weft threads 27 are at right angles to the warp threads 10. v

The last weft thread 27z picked but not removed is now brought into alignment with the beating front 16 by turning the warp beam 64 and the cloth beam and hence by uniform displacement of all the warp threads, as seen in FIGURE 4. Then the machine is again started up but the drive of the control and breast beam 72 as well as of the cloth beam, that is to say the uniform feed of all the warp threads, remains switched off. For this purpose, the rigid connection between the gearwheel 62 and the breast beam '72 is interrupted by means of a coupling not shown in the drawing and the breast beam is locked by means of this coupling so that it cannot turn either in one direction or in the other.

Since the machine is switched on, as mentioned, the journal of the gearwheel 61 is driven and the gearwheels 60, 61 and 62 rotate in the direction indicated by arrows in FIGURE 2; in addition, the shuttles 19 are displaced in the direction of the arrow and begin further picking.

Before the machine is switched on, the three-way cock 55 is also brought into that position in which the line 47 is connected to the source of compressed air while the line 48 is vented. Thus the piston 44 is acted on from the front and tends to displace the rod 50 towards the rear as a result of which the pawl 58 is lifted from the stop 75 and comes into engagement with the ratchet wheel 59 as a result of which further displacement is prevented at the moment the machine is switched on. The ratchet wheel 59 is turned step-by-step through the rotating gearwheels 60,61 and 62.

As already explained in the first example, the angle of rotation covered by the ratchet wheel 59 during each escapement step of the gearwheels 60, 61 and 62 which are intended for the cloth feed, depends on the density of weft threads. On the rotation of the ratchet wheel, the bell-crank lever 56 also rotates in clockwise direction under the action of the piston 44 as shown in FIGURE 2, as a result of which the two deflection rolls 65 and 71 are turned back step-by-step into their initial position through rod 50, bell-crank lever 83, link 85, lever 78a and the links 79 and 80. In consequence, the path of the warp threads 10 from the warp beam 63 to the beating front 16 has been shortened by an amount which increases from right to left and the path of these warp threads 10 from the beating front 16 to the cloth beam has been lengthened by the same amount so that these warp threads 10 have experienced a feed by this amount increasing from right to left in the region of the beating front 16. The weft threads 27 already picked, the last of which was the thread 27z, have therefore step-by-step again reached their original inclined position as shown in FIGURE 3. During the same time, that shuttle 19 which, when the machine was started up again, began to pick a new weft thread 271' at the left-hand edge of the width of the cloth immediately behind the beating front 16 and behind the weft thread 27z displaced backwards, has picked this weft thread 27i over the whole width of the cloth. At this moment, the position of this weft thread in relation to the beating front 16 corresponds to that of the weft thread 27a in FIGURE 3.

FIGURE 5 shows the position of this thread involved in being picked at the moment when the shuttle 19 delivering this thread has travelled somewhat more than the distance between two successive shuttles 19 and the weft threads already picked, up to and including the weft thread 27z, have regained somewhat more than a quarter of their original inclined position as a result of the different forward displacement of the warp threads 10. As a result, additional space for the picking of a further weft thread 27k, which has just begun, is afforded at the lefthand edge of the cloth in front of the beating front 16.

Once the thread 27i has been entirely picked and deflection rolls 65 and 71 have returned completely to their original positions, the coupling between breast beam 72 and gearwheel 62 is engaged so that breast beam and cloth beam are driven again and the machine continues to work without adjustment. As in the example first described, the angle between the beating front 16 and the picked weft threads depends on the density of weft threads and the spacing of the individual shuttles. Thus the initial position of the deflection rolls 65 and 71 illustrated in FIGURE 2 also depends on the density of the weft threads. Accordingly, this initial position can be set to the particular value necessary by means of the eccentric 54 which can be actuated by hand.

I claim:

1. A wave weaving loom comprising a cloth feed roll, beating-up members forming a beating front, a cloth having a beat-up line, inserted weft threads, an angular space between said weft threads and said beating front in normal weaving position of the loom, a source of power, a drive member powered by said source of power in order to displace the beating front and the inserted weft threads relative to one another and to form said angular space during resuming weaving after interruption of weaving due to a weft defect and control means, said control means being connected on one hand to said cloth feed roll and on the other hand to said drive member to control the speed of said drive member depending on the speed of rotation of said cloth feed roll, said control means having a coupling effective only in one direction of rotation.

2. A loom as claimed in claim 1 wherein said coupling comprises a pawl and a ratchet wheel, a pivotally mounted bell-crank lever to which said pawl is articulated, a rack on said drive member displaceable in its longitudinal direction, said lever having a toothed segment in mesh with said rack, a fixed stop and an adjustable stop for said rack, a double-acting piston for displacing said rack actuated by said source of power in one direction towards said fixed stop and in the opposite direction towards said adjustable stop, the angular position of said heating front in relation to said inserted weft threads being determined by said adjustable stop.

3. A loom as claimed in claim 2 wherein said ratchet wheel is connected through gear wheels to said cloth feed roll.

4. A loom as claimed in claim 1 wherein said control means and said source of power are connected to said beating-up members through said drive member.

5. A loom as claimed in claim 1 wherein said control means and said source of power are connected through said drive member to members for changing the direction of the inserted weft threads.

References Cited UNITED STATES PATENTS 720,181 2/1903 Salisbury 139-12 1,161,979 11/1915 Salisbury 139--12 1,889,076 11/1932 Mutter 139-12 2,144,947 1/1939 Valentine 13912 3,255,782 6/1966 Fend 139l2 3,346,017 10/1967 Fend 13912 JAMES CHI, Primary Examiner U.S. Cl. X.R. 

